1. Field of the Invention
The present invention relates to a nozzle assembly for a rocket and/or ramjet which is constructed to effect large changes in the nozzle throat area with minimal actuation forces and component mass.
2. Description of Related Art
Many different types of constructions and techniques are in the prior art for controlling the throat area in a nozzle assembly for rocket and/or ramjet applications to effect thrust and thrust vectoring control. Illustrative examples of such constructions and techniques are set forth in the patents described hereinafter.
U.S. Pat. No. 3,570,247 discloses a jet nozzle having a center body provided with flaps 19 that are movable to divert the flow of gases for thrust-spoiling or thrust-reversing.
U.S. Pat. No. 4,753,392 discloses a gas turbine engine exhaust nozzle including a pair of spaced-apart converging flaps which are rotatable about their respective axes to block or unblock the outlet ports.
U.S. Pat. No. 4,760,960 discloses in FIGS. 1a and 1b a pair of pivotable flap assemblies 16, 18 in a gas turbine exhaust nozzle for the purpose of controlling thrust.
U.S. Pat. No. 5,050,803 discloses an actuation system for positioning the divergent flaps of a vectorable two-dimensional exhaust nozzle.
U.S. Pat. No. 5,092,525 discloses a gas turbine engine exhaust nozzle comprising converging flaps each being operably connected through an actuation mechanism, to respective doors which block respective reverse thrust outlets.
U.S. Pat. No. 5,690,280 discloses a jet aircraft nozzle having thrust reversing and thrust vectoring functions using two pairs of pivotable flaps.
U.S. Pat. No. 6,681,561 discloses an outlet device for a jet engine comprising two guide flaps 11 and 12 which are rotatable about a rotary axis extending substantially perpendicularly to the main flow direction, and at least one intermediate guide flap 14 which is provided between the two guide flaps 11 and 12, and which is rotatable about a rotary axis extending in parallel with the rotary axis of the guide flaps.
Although the constructions and techniques disclosed in the above-described patents have, in many cases, generally served their purpose, they are subject to one or more of the following disadvantages:
1. They are complicated in construction;
2. They are difficult and/or expensive to manufacture;
3. They are unreliable in operation;
4. The operating mechanisms are exposed to hot exhaust gases and thus are subject to deterioration;
5. They require large component mass and weight;
6. They require large forces to move the operating elements; and
7. They provide for only small throat area changes.
The new and improved nozzle assembly of the present invention is not subject to the above-described disadvantages and possesses significant advantages not found in the constructions and techniques disclosed in the prior art.